The ever-increasing demand for ammonia requires more advanced atomic catalysts with high-activity and high-loading active sites for the electrocatalytic nitrogen reduction reaction (NRR). Owing to ...the “accept and backdonate mechanism”, transition metal (TM) atoms are the preferred active sites. However, because of the fast self-nucleation of TM heteroatoms, the loading of active TM heteroatoms is relatively low. Thus, the research on intrinsic TM active sites is significant. Herein, using density functional theory calculations, intrinsic defects in the basal plane of WS2, including vacancy defects and antisite defects, were created with high-loading TM active sites for boosting NRR. As expected, antisite WS with one W atom replacing one S atom could catalyze NRR with a low potential of −0.24 V versus a reversible hydrogen electrode.
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•Nanoneedle catalysts with core-shell structure were formed at room temperature.•CeO2 adjusted and optimized the electronic structure of transition metal phosphides.•The catalysts ...exhibited excellent catalytic activities for both HER and OER.•The synthesized catalysts exhibited good structural stability.
The discovery of earth-abundant electrocatalysts to replace platinum and iridium for overall water splitting is a crucial step in reducing the cost of green hydrogen production. Transition metal phosphides have drawn wide attention due to their non-toxicity, good chemical stability, low cost, and stable catalytic activity in alkaline electrolytes. We report a three-dimensional flower-like structure composed of core-shell nanoneedles as catalysts, in which CeO2 is introduced on the surface of nickel cobalt bimetallic phosphide through electrodeposition. And X-ray photoelectron spectroscopy testing and DFT calculations show electron coupling and transfer between CeO2 and CoP3, thereby modulating the electronic structure of the catalyst surface and reducing the adsorption energy of H atoms during the catalytic process, resulting in enhanced catalytic activity. In 1 M KOH, it exhibits a low overpotential of 109 and 296 mV to achieve the current density of 50 mA cm−2 for HER and OER, respectively. When used as both cathode and anode as a bifunctional catalyst, a voltage of only 1.77 V is required to achieve a current density of 50 mA cm−2, demonstrating great industrial potential.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•3D CMCM is designed using wet etching and one-step hydrothermal methods.•3D CMCM/Li is obtained by simply pressing 3D CMCM into Li wafer.•3D CMCM has low nucleation overpotential and ensures uniform ...deposition of Li.•3D CMCM promotes reaction kinetics and inhibits growth of lithium dendrites.•The cell with 3D CMCM/Li possesses high CE and satisfactory cycle lifespan.
Lithium metal anodes (LMAs) are the prospective candidates for the future energy storage/conversion systems because of high theoretical capacity and the lowest negative potential. However, the instability of solid electrolyte interphase and the generation of lithium dendrites during the repeated plating/striping process have become the serious challenges for commercialization of LMAs. Herein, a composite anode is obtained by simply pressing three dimensional CuO@MnO2-modified copper mesh (3D CMCM) into Li foil, and named as 3D CMCM/Li. The lithiophilic 3D CMCM not only possesses a low nucleation overpotential but also ensures the uniform deposition of Li. Density functional theory (DFT) calculations also confirm the lithiophilic essence of both CuO and MnO2. Meanwhile, the 3D CMCM skeleton with nanowire arrays makes contributions to reducing the local current density and enhancing Li plating/stripping reversibility. Significantly, owing to the synergistic effect of lithiophilic CuO@MnO2 and unique 3D copper skeleton structure with nanowire arrays, the half-cell composed of 3D CMCM exhibits a satisfactory Coulombic efficiency (CE, 99.6 %) and the cycle life (300 cycles) at 1 mAh cm−2. And the symmetric cell with 3D CMCM/Li exhibits a low voltage hysteresis and a long cycle stability of 3100 h at 1 mA cm−2/1 mAh cm−2. Moreover, the full cells assembled with sulfur-nitrogen, sulfur, and phosphorus co-doped carbon (S-NSPC) and LiFePO4 (LFP) cathodes possess the good cycling and rate performance. It is worth noting that the 3D CMCM/Li composite anode designed in this work offers an additional inspiration for the development of LMAs in the future.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
At the stage of hydrothermal process, we observed that the escape of crystal water would lead to the increase of oxygen vacancies in the material. The oxygen enriched VO2 was obtained by controlling ...the hydrothermal time reasonably. Combined with the in-situ electrochemical oxidation strategy, the energy storage of aqueous zinc ions was assisted.
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•New mechanism of oxygen vacancy formation.•The escape of lattice water leads to the increase of oxygen vacancies in materials.•Oxygen vacancy can promote the lattice reconstruction process of in-situ electrochemical oxidation process.•The specific capacity of oxygen-deficient V2O5/V2O5·nH2O can reach 376 mAh/g at 20 A/g.
Finding a cathode with high capacity and rate performance is very important for the large-scale application of low-cost and safe aqueous zinc-ion batteries (AZIBs). In this work, VO2 containing oxygen rich vacancies (VO) was designed through fine regulation of the hydrothermal reaction, which was mainly due to the escape of crystalline water in the material. The rich oxygen vacancies in VO will adsorb water molecules in electrolyte and have redox reaction with water molecules, thus promoting the in-situ lattice reconstruction process. On the first charge of in-situ electrochemical oxidation process, VO undergoes a complete phase transition to an oxygen-deficient V2O5/V2O5·nH2O (O-VO), allowing subsequent (de)intercalation of zinc cations on the basis of the latter structure. The electrode thus has significant rate performance (376 mAh/g at 20 A/g). The energy density/power density at 20 A/g is 274 Wh kg−1/14550 W kg−1. This work provides fundamental insights into the formation of oxygen vacancies in materials, and for the first time combines defect engineering with in-situ electrochemical oxidation strategies, providing an innovative design strategy for constructing cathodes with high-rate capacity and high energy storage.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The filtration membranes for selective separating mixture of fluids or particles are of great importance to numerous fields, ranging from pharmaceutical industries, automotive industry, and chemical ...engineering to individual protection. However, current membranes are difficult to simultaneously attained high separation efficiency, high flux, and easy to scale up, which have restricted their practical applications. Herein, we have prepared the neuron-like polyurethane nanofibrous materials with numerous cavities among fibers and beads. The resultant membranes exhibited underoil superhydrophobicity (163°), extremely low adhesion force (1.13 μN), and sliding angle (1.7°). The superwettability, small pore size, high porosity, and interconnected pore channel endowed the membranes with good separation performance towards water-in-oil emulsions, including high separation efficiency of 99.44%, permeation flux of 3874 L m−2 h−1, and good reusability in 15 cycles. In addition, the neuron-like PU nanofibrous membranes presented intriguing waterproof performance with water vapor transmission rate of 10592.3 g m−2 d−1. Furthermore, the neuron-like PU nanofibrous membranes exhibited superior separation performance towards both sodium chloride and oily aerosol particles with filtration efficiency >99.99%, pressure drop of ∼90 Pa, and quality factor value > 0.1. The good selective separation performance of prepared PU nanofibrous membranes paves a way for fabricating filters for the separation of air/particles, oil/particles, emulsions, and water/moisture in different fields.
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•The robust neuron-like PU nanofibrous membranes were fabricated by electrospinning•The PU nanofibrous membranes exhibited superwettability to water and oil.•The membranes exhibited intriguing separation performance towards W/O emulsions.•The membrane presented good waterproof and air/oily aerosols filtration performance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Lithium‐sulfur batteries (LSBs) are recognized as the prospective candidate in next‐generation energy storage devices due to their gratifying theoretical energy density. Nonetheless, they still face ...the challenges of the practical application including low utilization of sulfur and poor cycling life derived from shuttle effect of lithium polysulfides (LiPSs). Herein, a hollow polyhedron with heterogeneous CoO/Co9S8/nitrogen‐doped carbon (CoO/Co9S8/NC) is obtained through employing zeolitic imidazolate framework as precursor. The heterogeneous CoO/Co9S8/NC balances the redox kinetics of Co9S8 with chemical adsorption of CoO toward LiPSs, effectively inhibiting the shuttle of LiPSs. The mechanisms are verified by both experiment and density functional theory calculation. Meanwhile, the hollow structure acts as a sulfur storage chamber, which mitigates the volumetric expansion of sulfur and maximizes the utilization of sulfur. Benefiting from the above advantages, lithium‐sulfur battery with S‐CoO/Co9S8/NC achieves a high initial discharge capacity (1470 mAh g−1 ) at 0.1 C and long cycle life (ultralow capacity attenuation of 0.033% per cycle after 1000 cycles at 1 C). Even under high sulfur loading of 3.0 mg cm−2 , lithium‐sulfur battery still shows the satisfactory electrochemical performance. This work may provide an idea to elevate the electrochemical performance of LSBs by constructing a hollow metal oxide/sulfide/nitrogen‐doped carbon heterogeneous structure.
A novel hollow polyhedron with a heterogeneous CoO/Co9S8/NC has been successfully synthesized, and used as a sulfur host. The heterogeneous CoO/Co9S8/NC balances the redox kinetics of Co9S8 and chemical adsorption of CoO toward LiPSs, and effectively inhibits the shuttle of LiPSs, leading to the improved reversible capacity and durable cyclability for LSBs.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Based on a bandgap thermodynamic approach, the thickness-dependent bandgap of two-dimensional transition metal dichalcogenides is modeled without any adjustable parameter. An efficient expansion in ...bandgap upon lowering the thickness is predicted. The thickness-dependence of bandgap is believed originated from the interlayer van der Waals (vdW) interaction, while the surface effect is characterized by the difference in atomic thermal vibration between the surface and the interior. Due to the suppression role of the interlayer vdW interaction on the thermal vibration of interior chalcogen atoms, the surface effect is variable, which changes from monotonic increase for sulfides to decrease for tellurides. The role of the interlayer vdW interaction depends on the polarity of metal-chalcogen bonds. The model predictions agree with available experiment and simulation results.
•A model is established to illustrate the thickness-dependent bandgap of transition metal dichalcogenides.•A convincing method is developed to characterize the surface effect of 2D layered materials.•The role of interlayer vdW interaction in thickness-dependence of bandgap of transition metal dichalcogenides is unraveled.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
1T/2H-MoSe2 nanosheets are uniformly grown on the external surface and inner wall of nitrogen and sulfur co-doped mesoporous hollow carbon spheres (MoSe2-NSHC) by a simple hydrothermal method. ...Lithium-sulfur battery with a MoSe2-NSHC-PP separator and a MoSe2-NSHC/S cathode exhibits an excellent cycle performance.
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•MoSe2-NSHC is used as both sulfur host and modified material of separator.•MoSe2-NSHC accelerates kinetics conversion of lithium polysulfides.•MoSe2/NSHC-based Li-S battery displays good electrochemical performance.
Due to the dissolution, shuttling, and tardy kinetics conversion of lithium polysulfides (LiPSs) during cycling, there are serious defects in the utilization of active material and capacity retention ability for lithium-sulfur batteries (LSBs). To inhibit effectively the shuttling effect of LiPSs, herein, we propose the dual design strategies, using 1 T/2H mixed phase MoSe2 (1 T/2H-MoSe2) nanosheets uniformly growing on the external surface and inner wall of nitrogen and sulfur co-doped mesoporous hollow carbon spheres (MoSe2-NSHC) as both sulfur host and modified material of conventional polypropylene (PP) separator. The hollow structure of MoSe2-NSHC has a large specific surface area and internal space, which not only loads a large amount of sulfur, but also buffers severe volume expansion of sulfur during charge/discharge process. Meanwhile, 1 T/2H-MoSe2 and co-doped nitrogen and sulfur in the carbon skeleton effectively anchor LiPSs and accelerate the kinetics conversion of LiPSs by forming chemical bond. Density-functional theory calculations indicate the corresponding mechanisms. Based on these advantages, lithium-sulfur battery assembled with a MoSe2-NSHC/S cathode and a MoSe2-NSHC-PP separator delivers an initial discharge capacity of 1402 mAh/g at 0.2C, and also exhibits the first discharge capacity of 1155 mAh/g at 0.5C with a capacity retention rate of 79 % after 100 cycles. And after 800 cycles at 1C, the outstanding long-term cyclability with a low capacity decay per cycle of 0.039 % is also obtained. Notably, even in case of sulfur loading of 3.2 mg cm−2 and electrolyte/sulfur ratio of 6 μL mg−1, lithium-sulfur battery still exhibits a good electrochemical performance. Importantly, this work provides a feasible approach for commercial application of LSBs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The efficient extraction of uranium is challenging for radioactive wastewater treatment. Concerning to the specific coordination of functional groups with radionuclides, the development of ideal ...sorbents with high surface area, enhanced porosity and abundant functional groups compatibly to uptake uranium selectively is of great significance. Biochar, an attractive material to concentration aquatic targets, exhibits a positive correlation of surface area and pore volume of biochars with pyrolysis temperature, whereas a negative relation of surface functionality with thermolysis temperature. Here we applied a facile and environmental-friendly ball-milling technique to engineer raw biochars in the presence of phytic acid. Ball-milling treatment increased the external surface area of biochars by reducing grain sizes, as well as enhanced the micropore surface area by exposing blocked micropore networks. P-containing moiety was grafted to the surface of biochar matrix successfully. The physicochemical characteristics of biochars enabled a high uptake capacity (128.5 mg/g) and favorable selectivity of U(VI). It suggested that ball-milling of raw biochars with activating solvents could achieve an excellent performance for the efficient concentration of aquatic uranium.
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•Ball-milling of raw biochar with phytic acid enables PO4 graft and enhanced porosity.•Biochar activating with 30 wt% phytic acid uptakes U(VI) efficiently and selectively.•U(VI)-loaded ball-milled biochar could be well regenerated and reused.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To explore the impact of ARGs on the prognosis of NSCLC, and its correlation with clinicopathological parameters and immune microenvironment. Preliminary research on the biological functions of CEBPA ...in NSCLC.BACKGROUNDTo explore the impact of ARGs on the prognosis of NSCLC, and its correlation with clinicopathological parameters and immune microenvironment. Preliminary research on the biological functions of CEBPA in NSCLC.Using consensus clustering analysis to identify molecular subtypes of ARGs in NSCLC patients; employing LASSO regression and multivariate Cox analysis to select 7 prognostic risk genes and construct a prognostic risk model; validating independent prognostic factors of NSCLC using forest plot analysis; analyzing immune microenvironment correlations using ESTIMATE and ssGSEA; assessing correlations between prognostic risk genes via qPCR and Western blot in NSCLC; measuring mRNA and protein expression levels of knocked down and overexpressed CEBPA in NSCLC using CCK-8 and EdU assays; evaluating the effects of knocked down and overexpressed CEBPA on cell proliferation using Transwell experiments; examining the correlation of CEBPA with T cells and B cells using mIHC analysis.METHODSUsing consensus clustering analysis to identify molecular subtypes of ARGs in NSCLC patients; employing LASSO regression and multivariate Cox analysis to select 7 prognostic risk genes and construct a prognostic risk model; validating independent prognostic factors of NSCLC using forest plot analysis; analyzing immune microenvironment correlations using ESTIMATE and ssGSEA; assessing correlations between prognostic risk genes via qPCR and Western blot in NSCLC; measuring mRNA and protein expression levels of knocked down and overexpressed CEBPA in NSCLC using CCK-8 and EdU assays; evaluating the effects of knocked down and overexpressed CEBPA on cell proliferation using Transwell experiments; examining the correlation of CEBPA with T cells and B cells using mIHC analysis.Consensus clustering analysis identified three molecular subtypes, suggesting significant differential expression of these ARGs in NSCLC prognosis and clinical pathological parameters. There was significant differential expression between the two risk groups in the prognostic risk model, with P < 0.001. The risk score of the prognostic risk model was also P < 0.001. CEBPA exhibited higher mRNA and protein expression levels in NSCLC cell lines. Knockdown of CEBPA significantly reduced mRNA and protein expression levels of CEBPB, YWHAZ, ABL1, and CDK1 in H1650 and A549 cells. siRNA-mediated knockdown of CEBPA markedly inhibited proliferation, migration, and invasion of NSCLC cells, whereas overexpression of CEBPA showed the opposite trend. mIHC results indicated a significant increase in CD3 + CD4+, CD3 + CD8+, and CD20 + cell counts in the high CEBPA expression group.RESULTSConsensus clustering analysis identified three molecular subtypes, suggesting significant differential expression of these ARGs in NSCLC prognosis and clinical pathological parameters. There was significant differential expression between the two risk groups in the prognostic risk model, with P < 0.001. The risk score of the prognostic risk model was also P < 0.001. CEBPA exhibited higher mRNA and protein expression levels in NSCLC cell lines. Knockdown of CEBPA significantly reduced mRNA and protein expression levels of CEBPB, YWHAZ, ABL1, and CDK1 in H1650 and A549 cells. siRNA-mediated knockdown of CEBPA markedly inhibited proliferation, migration, and invasion of NSCLC cells, whereas overexpression of CEBPA showed the opposite trend. mIHC results indicated a significant increase in CD3 + CD4+, CD3 + CD8+, and CD20 + cell counts in the high CEBPA expression group.The risk score of the prognostic risk model can serve as an independent prognostic factor, guiding the diagnosis and treatment of NSCLC. CEBPA may serve as a potential tumor biomarker and immune target, facilitating further exploration of the biological functions and immunological relevance in NSCLC.CONCLUSIONSThe risk score of the prognostic risk model can serve as an independent prognostic factor, guiding the diagnosis and treatment of NSCLC. CEBPA may serve as a potential tumor biomarker and immune target, facilitating further exploration of the biological functions and immunological relevance in NSCLC.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
